Nowadays, the world's manufacturing industries have evolved significantly. Environmental problems have emerged, and the negative effects of their activities on the environment are becoming increasingly apparent. Thus, green initiatives such as green purchasing have become necessary to minimize manufacturing's environmental impact. These initiatives aim to reduce waste, promote sustainability, and protect natural resources. The research aims to examine and explore how government regulations, top management support, supplier relationships, customer pressures, and expected business benefits affect the adoption of green purchasing (GP) in manufacturing companies in Oman. It also aims to evaluate how this adoption influences environmental performance. Additionally, the research aims to examine GP practices among various organizations in Oman and identify which factors positively or negatively impact GP adoption. The research proposes a conceptual framework consisting of five factors that influence GP: government regulations, top management support, supplier relationships, customer pressures, and expected business benefits. The research hypothesizes that all factors positively influence GP and that adoption impacts environmental performance. Data was collected using an online questionnaire of 202 employees from different manufacturing companies in Oman. The online questionnaire is more suitable than other methods because it is convenient for respondents and confidential. IBM SPSS and SmartPLS software were used in this research. The research findings support that government regulations, top management support, supplier relationships, and expected business benefits significantly influence the adoption of GP, leading to improved environmental performance. However, customer pressures do not have an impact on green practice adoption. This research offers valuable theoretical contributions as one of the earliest studies in Oman and the GCC to investigate GP adoption determinants and their influence on environmental performance. It also introduces a versatile conceptual model with potential applicability across diverse industries. Furthermore, it provides practical contributions and a comprehensive overview and understanding for managers and decision-makers.